I'd like to see an SC in Lee Vining as well, for travel over Tioga Pass and into the eastern part of Yosemite National Park (Tuolumne Meadows). However, with HPWCs in Lee Vining (hopefully, as mentioned above) and SCs in Mammoth and Topaz Lake, a Model S/X with dual chargers should still be able to get enough charge in a reasonable amount of time.
With only HPWCs in Lee Vining (they'd better be 80A to be useful), getting a full charge in Lee Vining would be problematic, as I doubt the deli will want owners camping out there for that long. Typically, people are there for well under two hours (if they have a meal, much less if they just get gas and/or buy some tourist junk). With only HPWCs at the deli, about all you can hope for is enough charge to get you back to Yosemite Valley, or to Mammoth after 15-30 minutes if Tesla puts an SC in Jamestown instead of Groveland. HPWCs at the deli will make round trips from Tuolumne Meadows to the deli/Mono Lake possible, even if they don't get some EVSEs at the Meadows.
I am assuming that, prior to topping off in Lee Vining, the battery has been fully charged at either the Topaz Lake SC (~70 miles away) or the Mammoth SC (~28 miles away). So the amount of time needed at an 80A HPWC should be reasonable, even if not ideal.
That's almost certainly true in winter, but the traffic counts show 120 has heavier use year round - see http://www.dot.ca.gov/hq/traffops/census/docs/2014_aadt_volumes.pdf . Dodge Ridge is reachable by a 60 even when fully loaded in winter from the Manteca SC. HPWCs, J1772s or just 14-50s are the appropriate choice for ski resorts.
You don't need charging at Tuolumne Meadows if you have a SC in Lee Vining. It's only 21 miles (28 RM) to the Meadows (9000 ft) and downhill from there.
Even Manteca to Lee Vining can be a nail biter in a 60 (especially if the temp is <=50 deg.). Manteca to Mammoth is basically out of the question, even at a speed multiplier of 1.0, temp 72 deg. and with only 200 lb. in the car - EVtripplanner shows it taking 214 RM. Not to mention that from Manteca to either town takes a range charge, so you'll be sitting in Manteca for a long time. IMO, SCs shouldn't be spaced further apart than can be reached in a 60 when charged to 80%, fully loaded, year-round conditions and including a reserve (I'd plan on 10% rounded up to the nearest multiple of 5 miles). Or, at most, you should be able to reach the next SC in good conditions with an 80% charge, and be able to reach it with 90% in poor conditions. That gives you some cushion to charge more as the battery ages, without having to sit there forever.
I was up there on September 7th, and did a bit more scouting around. There is a little power in the campground, although I'm not sure of the source. Both the entrance kiosk and the campground reservations building have power, as well as a couple of RV panels for the campground hosts; there's also an RV panel behind the campground reservation building, with a NEMA 5-15 and a 10-30 receptacle, although it's not generally used (the 5-15 had an air quality monitoring instrument hooked up to it while I was there, for the smoke from the big fires). There's a transformer adjacent to the cafe' (west end, between it and the bathrooms, which have 5-15 receptacles) and also one along the east side of the gas station lot. The Visitor Center, Wilderness Permit Center and Ranger Stations also have power, as does Tuolumne Lodge. The x-former near the gas station is only 250kVA IIRR, and I couldn't find any labels on the one near the cafe'/store.
Well, the campground hosts' RV panels with 10-30s/5-15s are out of bounds (I made specific arrangements for a MNL LEAF owner to use one of the 5-15s back in 2012 with the Campground ranger, as part of a test), the 10-30 behind the campground res. office requires at least a 50' extension cord (100' would be better) to access and would be entirely unofficial (it's in an area designated for 'employee parking only'), and the 250 kVA transformer has to run the gas station, so I'd suspect they'd need to upgrade it. So, doable, but requires a fair amount of work.
While charging stops do increase the overall travel time, they can't be equated with something that adds to the drive time. Resting en route while picking up some charge is less burdensome than many might think. On the other hand, being stuck in traffic for an extra hour does sap one's energy.
